One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,8)(3,6,4,7)(25,26,31,36)(27,32,39,33)(28,38,37,34)(29,35,40,30)(1,2)(3,6)(4,7)(5,8)(9,10,14,15)(11,13,17,22)(12,16,21,23)(18,20,19,24)(25,27,31,39)(26,32,36,33)(28,29,37,40)(30,38,35,34)(1,3,5,4)(2,6,8,7)(10,15)(13,22)(16,23)(20,24)(25,27,31,39)(26,33,36,32)(28,29,37,40)(30,34,35,38)(9,11,14,17)(10,13,15,22)(12,19,21,18)(16,24,23,20)(25,28)(26,34)(27,29)(30,32)(31,37)(33,35)(36,38)(39,40)(1,3,5,4)(2,6,8,7)(9,12,14,21)(10,16,15,23)(11,18,17,19)(13,20,22,24)(25,29)(26,35)(27,37)(28,39)(30,36)(31,40)(32,34)(33,38)(1,4,5,3)(2,7,8,6)(9,13)(10,17)(11,15)(12,20)(14,22)(16,19)(18,23)(21,24)(25,30,31,35)(26,29,36,40)(27,38,39,34)(28,32,37,33)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.